US20110038178A1 - Planar illumination device - Google Patents
Planar illumination device Download PDFInfo
- Publication number
- US20110038178A1 US20110038178A1 US12/848,350 US84835010A US2011038178A1 US 20110038178 A1 US20110038178 A1 US 20110038178A1 US 84835010 A US84835010 A US 84835010A US 2011038178 A1 US2011038178 A1 US 2011038178A1
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- US
- United States
- Prior art keywords
- light guide
- guide plates
- unit light
- section
- illumination device
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0075—Arrangements of multiple light guides
- G02B6/0078—Side-by-side arrangements, e.g. for large area displays
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Planar Illumination Modules (AREA)
Abstract
A planar illumination device includes: a light guide plate formed by arranging a plurality of unit light guide plates each having a light emission surface as a front surface and a reflection surface as a back surface so that facing end surfaces of adjacent unit light guide plates of the plurality of unit light guide plates are closely arranged; and one or two or more light sources arranged on a side surface, in a direction where the plurality of unit light guide plates are arranged, of each of the plurality of unit light guide plates, in which a projection section is arranged on one of facing surfaces of two adjacent unit light guide plates in the arrangement direction and a recession section in which the projection section is engaged is arranged on the other of the facing surfaces of the two adjacent unit light guide plates.
Description
- The present application claims priority to Japanese Priority Patent Application JP 2009-186733 filed in the Japan Patent Office on Aug. 11, 2009, the entire content of which is hereby incorporated by reference.
- The present application relates to a planar illumination device performing large surface emission by successively arranging a plurality of unit light guide plates.
- In recent years, liquid crystal display panels, advertising panels for indoor and outdoor uses, signboards and the like become larger, and accordingly, thinner and larger planar illumination devices as backlights of these apparatuses are necessary. To achieve a thinner planar illumination device, for example, a light guide plate including a first light guide section and a second light guide section which is thinner than the first light guide section and has a surface recessed toward an emission surface on a side opposite to an emission surface is formed. For example, as described in Japanese Unexamined Patent Application Publication No. 2009-37744, there is proposed a method of arranging a base plate in a recession part recessed toward the emission surface of the second light guide section, and containing the light guide plate and the base plate in a frame made of a thin metal plate. Thereby, a balance between a reduction in profile of the light guide plate and rigidity of a liquid crystal panel is achievable.
- With regard to upsizing of a light guide plate, it is difficult to form one large light guide plate, and the cost of forming the large light guide plate is high. Therefore, a method of forming a large surface light source by successively arranging a plurality of unit light guide plates is considered. In this method, the large surface light source is manufactured more easily than a method using a large light guide plate, and cost reduction is achievable. However, in the case where a plurality of light guide plates are successively arranged to form a large surface light source, when the large surface light source emits light, a very small amount of illumination light is leaked from a connection section between the light guide plates to cause scattering in a boundary surface, thereby a bright line may be generated in the connection section.
- As one technique for solving such an issue, for example, as described in Japanese Unexamined Patent Application Publication No. 2007-213951, there is proposed a technique in which thin ends which are connection parts of unit light guide plates are formed in a recessed-and-projected shape, and a diffusion sheet is arranged on the unit light guide plates, thereby a bright line leaked from a gap between the connection parts is dispersed.
- Typically, a light guide plate of this kind is manufactured by an injection molding method. A light guide plate manufactured by the injection molding method is formed by introducing a resin into a mold from an inlet called a gate and then molding the resin by application of pressure or heat, but a resin introduction section at the gate is cut off in a later step.
- However, in a step of cutting off the resin introduction section at the gate, it is difficult to completely cut off the resin in a gate section, thereby the resin slightly remains. Therefore, in related art, when a plurality of unit light guide plates are successively arranged, a gap between the unit light guide plates is formed due to the remaining resin, thereby light is leaked from the gap to generate a bright line. Even if the leaked light is dispersed by arranging a diffusion sheet on the light guide plate, the leaked light is spread out to reduce the brightness of the leaked light, but a part corresponding to the bright line is clearly and highly visible.
- It is desirable to provide a planar illumination device allowed to inhibit bright line generation due to light leakage between unit light guide plates.
- According to an embodiment, there is provided a planar illumination device including: a light guide plate formed by arranging a plurality of unit light guide plates each having a light emission surface as a front surface and a reflection surface as a back surface so that facing end surfaces of adjacent unit light guide plates of the plurality of unit light guide plates are closely arranged; and one or two or more light sources arranged on a side surface, in a direction where the plurality of unit light guide plates are arranged, of each of the plurality of unit light guide plates, in which a projection section is arranged on one of facing surfaces of two adjacent unit light guide plates in the arrangement direction and a recession section in which the projection section is engaged is arranged on the other of the facing surfaces of the two adjacent unit light guide plates. More specifically, for example, the projection section corresponds to a remaining part formed when a gate section is cut off in the case where the unit light guide plates are manufactured by injection molding.
- In the planar illumination device according to an embodiment, the projection section of one unit light guide plate is engaged in the recession section arranged on a surface, facing the one unit light guide plate, of the other unit light guide plate, thereby the remaining part formed when cutting off the gate section of the light guide plate manufactured by injection molding is avoidable, and adjacent unit light guide plates are arranged sufficiently closely.
- In the planar illumination device according to an embodiment, a projection section is arranged on one of facing surfaces of two unit light guide plates arranged adjacent to each other and a recession section in which the projection section is engaged is arranged on the other of the facing surfaces of the two unit light guide plates. Therefore, for example, a remaining part formed when cutting off the gate section of the light guide plate manufactured by injection molding is not sandwiched between two unit light guide plates, and adjacent unit light guide plates are allowed to be arranged sufficiently closely, and light leakage between the unit light guide plates is allowed to be reduced. In other words, bright light generation is allowed to be inhibited.
- Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures.
-
FIG. 1 is a perspective view illustrating a schematic configuration of a planar illumination device according to a first embodiment. -
FIGS. 2A and 2B are a plan view and a sectional view illustrating a light guide plate illustrated inFIG. 1 . -
FIG. 3 is a side view illustrating a configuration of a reflection surface of a light guide plate. -
FIG. 4 is a perspective view illustrating a schematic configuration of a liquid crystal display including the planar illumination device according to the first embodiment. -
FIGS. 5A and 5B are a plan view and a sectional view illustrating a light guide plate according to a second embodiment. -
FIGS. 6A and 6B are a plan view and a sectional view illustrating a light guide plate according to a modification. - The present application will be described in detail below referring to the accompanying drawings according to an embodiment. Descriptions will be given in the following order.
- (1) First Embodiment (An example in which a planar surface has a recession and a projection)
- (2) Second Embodiment (An example in which a planar surface and a longitudinal sectional surface has a recession and a projection)
- (3) Modification
-
FIG. 1 is a perspective view illustrating a configuration of a main part of aplanar illumination device 1 according to a first embodiment. Theplanar illumination device 1 is used as, for example, a backlight of a liquid crystal display or the like, and in theplanar illumination device 1, alight guide plate 10 is formed by closely arranging a plurality of unit light guide plates in one or two or more lines. Here, thelight guide plate 10 configured of two unitlight guide plates - In the
planar illumination device 1, a plurality of (in this case, five)light sources 13 are arranged on a side surface along an x direction of each of the unitlight guide plates light guide plates light guide plates light guide plates - The unit
light guide plates light source 13 to the light emission surface S2. The unitlight guide plates light guide plates light source 13. In other words, the material of the unitlight guide plates light guide plates light guide plates - As the
light sources 13, for example, LEDs (Light Emitting Diodes) or fluorescent lamps are used. The number oflight sources 13 for each of the unitlight guide plates light guide plates light sources 13 on each of the unitlight guide plates light guide plates light sources 13 may be arranged on both facing side surfaces, or thelight sources 13 may be arranged on not only one side surface but also still another side surface. -
FIG. 2A illustrates a plan view of the unitlight guide plates FIG. 2B illustrates a sectional view of the unitlight guide plates FIG. 2A .Projection sections light guide plates projection sections projection sections light guide plates FIG. 1 . On the other hand,recession sections light guide plates projection sections recession sections recession sections projection sections projection sections recession sections - As illustrated in
FIG. 3 , a lightguide control section 14 is arranged on the reflection surface S1 of each of the unitlight guide plates guide control section 14 controls the guide of light entering from thelight source 13 to each of the unitlight guide plates guide control section 14 has an inclined surface (an inclined angle α) inclined with respect to thelight source 13, and includes a plurality of projection sections 14A extending in an X direction. The inclined angle is an angle which an inclined surface facing thelight source 13 forms with a bottom surface. The projection sections 14A of the lightguide control section 14 may be arranged at regular intervals or different intervals. The inclined angles α of the plurality of projection sections 14A are, for example, the same as one another. For example, the projection sections 14A are arranged so that the heights H (distances from the bottom surface to the top of a projected structure) of the projection sections 14A gradually increase with distance from thelight source 13. - When such a light
guide control section 14 is arranged, a uniform light emission strength distribution as a whole light guide plate is allowed to be formed. -
FIG. 4 illustrates a schematic configuration of a liquid crystal display including theplanar illumination device 1, and the liquid crystal display includes adiffusion sheet 15 and aliquid crystal panel 16 on thelight guide plate 10 configured of the above-described unitlight guide plates - In the
planar illumination device 1 according to the embodiment, when each of the plurality oflight sources 13 emits light, light enters into each of the unitlight guide plates light guide plates light guide plates light guide plates planar illumination device 1. - In this case, each of the
projection sections light guide plates recession sections projection sections light guide plates - As described above, in the embodiment, each of the
projection sections light guide plates recession sections projection sections light guide plates light guide plates - Moreover, variations in gate sections formed in the cutting off step are acceptable by adjusting the shapes and sizes of the
recession sections projection sections -
FIG. 5A illustrates a plan view of alight guide plate 20 of aplanar illumination device 2 according to a second embodiment.FIG. 5B illustrates a sectional view of thelight guide plate 20 taken along an alternate long and short dash line inFIG. 5A . Thelight guide plate 20 is configured of two unitlight guide plates light guide plates projection sections recession sections light guide plates - In the embodiment, as in the case of the first embodiment, the
projection sections light guide plates projection sections projection sections light guide plates recession sections light guide plates projection sections light guide plates - As described above, in the embodiment, a recessed-and-projected structure (the
projection sections sections light guide plates light guide plates light guide plates - In particular, in the embodiment, a recessed-and-projected structure along a vertical direction is arranged, so when viewed from above, a gap is not formed between the unit
light guide plates - Although the present application is described referring to the first and second embodiments, the application is not limited thereto, and may be variously modified. For example, in the second embodiment, the longitudinal sectional shape of the recession section arranged in each of the unit
light guide plates FIG. 5B , and the recession section may have any shape, as long as the recession section is allowed to avoid theprojection section 22A. More specifically, as illustrated inFIGS. 6A and 6B , arecession section 31B having an inclined surface is arranged. Even in such a recessed-and-projected structure, the same functions and effects as those in the second embodiment are obtainable. - Moreover, light from the
light source 13 is not limited to visible light, and may be nonvisible light such as infrared light or ultraviolet light, and may be changed depending on intended use. - It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
Claims (3)
1. A planar illumination device comprising:
a light guide plate formed by arranging a plurality of unit light guide plates each having a light emission surface as a front surface and a reflection surface as a back surface so that facing end surfaces of adjacent unit light guide plates of the plurality of unit light guide plates are closely arranged; and
one or two or more light sources arranged on a side surface, in a direction where the plurality of unit light guide plates are arranged, of each of the plurality of unit light guide plates,
wherein a projection section is arranged on one of facing surfaces of two adjacent unit light guide plates in the arrangement direction and a recession section in which the projection section is engaged is arranged on the other of the facing surfaces of the two adjacent unit light guide plates.
2. The planar illumination device according to claim 1 , wherein
the plurality of unit light guide plates are formed by injection molding, and the projection section corresponds to a remaining part in a gate section for the injection molding.
3. The planar illumination device according to claim 1 , wherein
the light sources are arranged on two side surfaces of each of the plurality of unit light guide plates.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JPP2009-186733 | 2009-08-11 | ||
JP2009186733A JP2011040278A (en) | 2009-08-11 | 2009-08-11 | Planar illumination device |
Publications (2)
Publication Number | Publication Date |
---|---|
US20110038178A1 true US20110038178A1 (en) | 2011-02-17 |
US8408777B2 US8408777B2 (en) | 2013-04-02 |
Family
ID=43588504
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/848,350 Expired - Fee Related US8408777B2 (en) | 2009-08-11 | 2010-08-02 | Planar illumination device |
Country Status (3)
Country | Link |
---|---|
US (1) | US8408777B2 (en) |
JP (1) | JP2011040278A (en) |
CN (1) | CN101994955A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120182761A1 (en) * | 2009-10-09 | 2012-07-19 | Sharp Kabushiki Kaisha | Planar light source device |
US20120195071A1 (en) * | 2009-10-07 | 2012-08-02 | Sharp Kabushiki Kaisha | Light source module and electronic device including the same |
USRE45879E1 (en) | 2011-07-25 | 2016-02-02 | Seiko Epson Corporation | Lighting unit, liquid crystal display, and electronic apparatus |
US20160170132A1 (en) * | 2013-08-02 | 2016-06-16 | Sakai Display Products Corporation | Lighting Device and Display Apparatus |
US9798068B2 (en) | 2015-08-20 | 2017-10-24 | Keio University | Illumination module |
EP3951257A1 (en) * | 2020-08-03 | 2022-02-09 | Seat, S.A. | Lighting device |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TWI417587B (en) * | 2009-03-10 | 2013-12-01 | Au Optronics Corp | Light guide plate combination |
WO2013073458A1 (en) * | 2011-11-18 | 2013-05-23 | シャープ株式会社 | Illumination device, display device, and television reception device |
TWI550325B (en) * | 2012-12-21 | 2016-09-21 | 鴻海精密工業股份有限公司 | Back light module |
JP6334134B2 (en) * | 2013-01-11 | 2018-05-30 | 学校法人慶應義塾 | Lighting module |
KR102628018B1 (en) * | 2016-08-30 | 2024-01-24 | 엘지이노텍 주식회사 | Lighting module and lighting apparatus |
Citations (6)
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US20040105250A1 (en) * | 2002-11-29 | 2004-06-03 | Charles Leu | Light guide plate and backlight system using the same |
US20060221638A1 (en) * | 2005-04-01 | 2006-10-05 | Chew Tong F | Light-emitting apparatus having a plurality of adjacent, overlapping light-guide plates |
US20060245213A1 (en) * | 2003-03-31 | 2006-11-02 | Jurgen Beil | Method for the production of an illumination device and illumination device |
US20080205080A1 (en) * | 2007-02-23 | 2008-08-28 | Luminus Devices, Inc. | Tiled illumination assembly and related methods |
US7490963B2 (en) * | 2004-12-24 | 2009-02-17 | Innocom Technology (Shenzhen) Co., Ltd. | Diffusion plate and backlight module using the same |
US20100271806A1 (en) * | 2009-04-27 | 2010-10-28 | Lg Electronics Inc. | Back light unit and display device using the same |
Family Cites Families (4)
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JP2005317474A (en) * | 2004-04-30 | 2005-11-10 | Citizen Electronics Co Ltd | Backlight apparatus |
CN100371793C (en) * | 2004-12-09 | 2008-02-27 | 联准实业有限公司 | Large size back light module |
JP4652987B2 (en) | 2006-02-09 | 2011-03-16 | 富士フイルム株式会社 | Surface lighting device |
JP2009037744A (en) | 2007-07-31 | 2009-02-19 | Sony Corp | Illuminating device and liquid crystal display |
-
2009
- 2009-08-11 JP JP2009186733A patent/JP2011040278A/en not_active Abandoned
-
2010
- 2010-08-02 US US12/848,350 patent/US8408777B2/en not_active Expired - Fee Related
- 2010-08-03 CN CN2010102458374A patent/CN101994955A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040105250A1 (en) * | 2002-11-29 | 2004-06-03 | Charles Leu | Light guide plate and backlight system using the same |
US20060245213A1 (en) * | 2003-03-31 | 2006-11-02 | Jurgen Beil | Method for the production of an illumination device and illumination device |
US7490963B2 (en) * | 2004-12-24 | 2009-02-17 | Innocom Technology (Shenzhen) Co., Ltd. | Diffusion plate and backlight module using the same |
US20060221638A1 (en) * | 2005-04-01 | 2006-10-05 | Chew Tong F | Light-emitting apparatus having a plurality of adjacent, overlapping light-guide plates |
US20080205080A1 (en) * | 2007-02-23 | 2008-08-28 | Luminus Devices, Inc. | Tiled illumination assembly and related methods |
US20100271806A1 (en) * | 2009-04-27 | 2010-10-28 | Lg Electronics Inc. | Back light unit and display device using the same |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120195071A1 (en) * | 2009-10-07 | 2012-08-02 | Sharp Kabushiki Kaisha | Light source module and electronic device including the same |
US20120182761A1 (en) * | 2009-10-09 | 2012-07-19 | Sharp Kabushiki Kaisha | Planar light source device |
US8303153B2 (en) * | 2009-10-09 | 2012-11-06 | Sharp Kabushiki Kaisha | Planar light source device |
USRE45879E1 (en) | 2011-07-25 | 2016-02-02 | Seiko Epson Corporation | Lighting unit, liquid crystal display, and electronic apparatus |
US20160170132A1 (en) * | 2013-08-02 | 2016-06-16 | Sakai Display Products Corporation | Lighting Device and Display Apparatus |
US9829623B2 (en) * | 2013-08-02 | 2017-11-28 | Sakai Display Products Corporation | Lighting device and display apparatus |
US9798068B2 (en) | 2015-08-20 | 2017-10-24 | Keio University | Illumination module |
EP3951257A1 (en) * | 2020-08-03 | 2022-02-09 | Seat, S.A. | Lighting device |
Also Published As
Publication number | Publication date |
---|---|
CN101994955A (en) | 2011-03-30 |
US8408777B2 (en) | 2013-04-02 |
JP2011040278A (en) | 2011-02-24 |
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